Parking assist apparatus

ABSTRACT

The present invention provides a parking assist apparatus capable of improving convenience when a passenger of a vehicle gets on and off. According to the present invention, the parking assistance apparatus acquires information on parking candidate frames, and where an own vehicle can park, from a front camera, a right camera, a rear camera, and a left camera configured to acquire information on a surrounding environment of the own vehicle, and from surrounding environment information acquired by these cameras. The parking assistance apparatus detects surrounding environment information and of the parking candidate frames, and from the surrounding environment information and information on the parking candidate frames, and determines a target parking position where the own vehicle parks based on the information on the parking candidate frames, the surrounding environment information, and the preference information related to getting on and off of a passenger who rides on the own vehicle.

TECHNICAL FIELD

The present invention relates to an apparatus for assisting a parkingoperation of a vehicle.

BACKGROUND ART

As a parking position guidance system capable of guiding to a parkingposition that conforms to user's preference with high accuracy, and ofguiding to a parking position even in a parking lot that user has notused, PTL 1 describes a parking lot side device that is provided with aparking lot information DB storing parking tastes when a large number ofvehicles have parked in a parking lot and determines a parkinginstruction position based on the parking lot information DB and tasteinformation of a vehicle user transmitted from an in-vehicle parkingposition guide device.

CITATION LIST Patent Literature

PTL 1: JP 2013-117780 A

SUMMARY OF INVENTION Technical Problem

There is widely known a parking assist apparatus that assists any or allof a steering wheel operation, an accelerator operation, and a brakeoperation of a driver in order to assist guidance of a vehicle to atarget parking position when the driver parks the vehicle.

The parking assist apparatus first detects a place where an own vehiclecan park by analyzing environment information around the own vehicleacquired by an onboard sonar or an onboard camera in a parking lot, andnotifies that the parkable place has been detected in an onboard displaydevice such as a navigation system. A passenger such as a driverselects, among the parkable places displayed on the onboard displaydevice, a place to be parked as a target parking position by using aninput means of the onboard display device and starts parking assistance,so that the passenger can receive parking assistance when parking thevehicle in the target parking position.

However, in a current parking assist apparatus including PTL 1, there isa problem that a time for the passenger to get on and off aftercompletion of the parking is not considered. As an example, there is aproblem in convenience when the passenger gets on and off, such asguiding to a parking position where there is a puddle.

The present invention has been made in view of the above problem, and anobject of the present invention is to provide a parking assist apparatuscapable of improving convenience when a passenger gets on and off of avehicle.

Solution to Problem

In order to solve the above problem, for example, a configurationdescribed in the claims is adopted. While the present invention includesa plurality of means for solving the above problems, one example thereofincludes: an external information acquisition unit configured to acquireexternal information of an own vehicle; a parkable space informationacquisition unit configured to acquire information on a parkable spacewhere the own vehicle can park, from the external information acquiredby the external information acquisition unit; a parking environmentdetection unit configured to detect environment information of theparkable space from the external information and the parkable spaceinformation; a preference information storage unit configured to storepreference information related to getting on and off of a passenger whorides on the own vehicle; and a parking space determination unitconfigured to determine a parking space where the own vehicle is to beparked based on the parkable space information, the environmentinformation, and the preference information.

Advantageous Effects of Invention

According to the present invention, it is possible to improveconvenience when a passenger gets on and off. The problems,configurations, and effects other than those described above will beclarified by the description of the embodiment below.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view schematically showing a system configuration of anembodiment of a parking assist apparatus according to the presentinvention.

FIG. 2 is a block diagram showing a relationship between input andoutput signals of a parking-assist ECU shown in FIG. 1.

FIG. 3 is a block diagram showing an internal configuration of theparking-assist ECU shown in FIG. 1.

FIG. 4 is a view showing an outline of preference information for aparking position of a passenger.

FIG. 4A is a view showing a state of setting preference information fora parking position of a passenger.

FIG. 5 is a flowchart explaining an arithmetic processing procedure bythe parking-assist ECU 1 of the present invention.

FIG. 6 is a view describing an embodiment of parking assistance by theparking assist apparatus of the present invention.

FIG. 7 is a view describing an embodiment of parking assistance by theparking assist apparatus of the present invention.

FIG. 8 is a view describing an embodiment of parking assistance by theparking assist apparatus of the present invention.

FIG. 9 is a view describing an embodiment of parking assistance by theparking assist apparatus of the present invention.

FIG. 10 is a view describing an embodiment of parking assistance by theparking assist apparatus of the present invention.

FIG. 11 is a view describing an embodiment of parking assistance by theparking assist apparatus of the present invention.

FIG. 12 is a view describing an embodiment of parking assistance by theparking assist apparatus of the present invention.

FIG. 13 is a view describing an embodiment of parking assistance by theparking assist apparatus of the present invention.

DESCRIPTION OF EMBODIMENTS

An embodiment of a parking assist apparatus according to the presentinvention will be described with reference to FIGS. 1 to 13. FIG. 1 is aview schematically showing an embodiment of a parking assist apparatus,which is the parking assist apparatus according to the presentinvention.

As shown in FIG. 1, the parking assist apparatus is mounted on an ownvehicle 100, and composed of a parking-assist electronic control unit(ECU) 1, a front camera 2 mounted on a front side of the own vehicle100, a right camera 3 mounted on a right side of the own vehicle 100, arear camera 4 mounted on a rear side the own vehicle 100, a left camera5 mounted on a left side of the own vehicle 100, an electric powersteering device 6, a right front wheel speed sensor 11 configured todetect a wheel speed of a right front wheel 7, a right rear wheel speedsensor 12 configured to detect a wheel speed of a right rear wheel 8, aleft rear wheel speed sensor 13 configured to detect a wheel speed of aleft rear wheel 9, a left front wheel speed sensor 14 configured todetect a wheel speed of a left front wheel 10, an onboard display device15, a human sensor 16, and a vehicle control ECU 17.

The front camera 2, the right camera 3, the rear camera 4, and the leftcamera 5 are provided with a lens and an image pickup element, and areappropriately arranged so as to be able to acquire information on asurrounding environment (external information) by imaging thesurrounding environment of the own vehicle 100. Captured images capturedby the cameras 2, 3, 4, and 5 are transmitted to the parking-assist ECU1, and subjected to image processing.

The electric power steering device 6 includes a steering angle sensor 6a configured to detect a steering angle of a steering wheel 18, a motor(not shown) configured to support a steering torque serving as a torqueto change a direction of each wheel, and an electric power steering ECU(not shown) configured to control the steering torque. The electricpower steering device 6 controls the steering torque to support adriver's operation of the steering wheel, to change directions of theright front wheel 7, the right rear wheel 8, the left rear wheel 9, andthe left front wheel 10. The steering angle detected by the steeringangle sensor 6 a is transmitted to the parking-assist ECU 1.

The right front wheel speed sensor 11, the right rear wheel speed sensor12, the left rear wheel speed sensor 13, and the left front wheel speedsensor 14 respectively detect wheel speeds of the right front wheel 7,the right rear wheel 8, the left rear wheel 9, and the left front wheel10, and transmit the respective wheel speeds to the parking-assist ECU1. The parking-assist ECU 1 calculates a speed of the own vehicle 100based on the information of each wheel speed described above.

The onboard display device 15 includes a preference information storageunit 15 a and a screen 15 b.

The preference information storage unit 15 a is a storage device thatstores preference information 15 a 1 (see FIG. 4) when a passenger whorides on the own vehicle 100 gets on and off.

The screen 15 b displays images captured by the front camera 2, theright camera 3, the rear camera 4, and the left camera 5 and processedby the parking-assist ECU 1. For example, the screen 15 b displays alocation of a parking candidate of the own vehicle 100, surroundingenvironment information of the parking candidate, and a target parkingposition.

A pressure sensitive or an electrostatic touch panel is adopted as thescreen 15 b, enabling various input operations. In particular, by usingthe touch panel, the screen 15 b can input the preference information 15a 1 on parking of the passenger including the driver of the own vehicle100 (preference information input unit, see FIG. 4A), and the inputtedcontents are stored in the preference information storage unit 15 a andtransmitted to the parking-assist ECU 1 as necessary.

The human sensor 16 is an infrared sensor for example, detects presenceor absence of a passenger in the own vehicle 100 including a driver whodrives the own vehicle 100, and transmits the detection result to theparking-assist ECU 1.

The parking-assist ECU 1 determines a target parking position (a parkingspace, a target parking frame 1101 (see FIG. 11)) in consideration ofconvenience of the passenger at getting on and off based on datareceived from each sensor and the preference information storage unit 15a, and transmits to the onboard display device 15 and the vehiclecontrol ECU 17.

In order to assist a parking operation during parking at the targetparking position, the vehicle control ECU 17 outputs a target steeringangle to the electric power steering device 6, controls a travelingdirection of the own vehicle 100, outputs a required driving force to adriving force control ECU (not shown) configured to control the drivingforce of the own vehicle 100, controls a speed of the own vehicle 100 byoutputting a required braking force to a braking force control ECU (notshown) configured to control the braking force, and controls a shiftrange of the own vehicle 100 by issuing a request for a drive range or areverse range or a parking range to a shift-by-wire control deviceconfigured to control the shift range of an automatic transmission. Bycontrolling the own vehicle 100 with the vehicle control ECU 17, thedriver can receive appropriate parking assistance during the operationfor parking at the above target parking position.

FIG. 2 schematically shows an example of an internal configuration ofthe parking-assist ECU 1 shown in FIG. 1, and is a block diagram showinga relationship between input and output signals of the parking-assistECU 1 shown in FIG. 1.

The parking-assist ECU 1 is composed of an I/O LSI 1 a including an A/Dconverter, a CPU 1 b, and the like. As described above, to theparking-assist ECU 1, signals are inputted from the front camera 2, theright camera 3, the rear camera 4, the left camera 5, the electric powersteering device 6, the right front wheel speed sensor 11, the right rearwheel speed sensor 12, the left rear wheel speed sensor 13, the leftfront wheel speed sensor 14, the onboard display device 15, and thehuman sensor 16.

The parking-assist ECU 1 outputs a parking candidate calculated by apredetermined calculation process, environment information around theparking candidate, and the target parking position to the onboarddisplay device 15, and displays on the screen 15 b of the onboarddisplay device 15. Further, by outputting the target parking position tothe vehicle control ECU 17 as described above, it is possible for thedriver to receive appropriate parking assistance during the operationfor parking the vehicle at the target parking position.

FIG. 3 shows a configuration related to an internal functional blockconfiguration of the parking-assist ECU 1 shown in FIG. 1. Such afunctional block is realized by hardware, software, or a combinationthereof.

As shown in FIG. 3, the parking-assist ECU 1 has, as functions of theI/O LSI 1 a and the CPU 1 b shown in FIG. 2, a parkable positioncalculation unit 301, an own vehicle position estimation unit 302, aparking environment evaluation unit 303, and a target parking positioncalculation unit 304.

The own vehicle position estimation unit 302 calculates a speed of theown vehicle 100 from wheel speeds of the respective wheels 7, 8, 9, and10 received from the right front wheel speed sensor 11, the right rearwheel speed sensor 12, the left rear wheel speed sensor 13, and the leftfront wheel speed sensor 14, and calculates a traveling direction of theown vehicle 100 from a steering angle of the steering wheel receivedfrom the steering angle sensor 6 a of the electric power steering device6. Further, the vehicle position estimation unit 302 calculates acoordinate position of the own vehicle 100 from environment informationaround the own vehicle 100 captured by the front camera 2, the rightcamera 3, the rear camera 4, and the left camera 5, and from informationon the previously calculated vehicle speed and the traveling directionof the own vehicle 100, and transmits the coordinate position of the ownvehicle 100 to the parkable position calculation unit 301 and theparking environment evaluation unit 303.

The parkable position calculation unit 301 analyzes environmentinformation around the own vehicle 100 captured by the front camera 2,the right camera 3, the rear camera 4, and the left camera 5, andcalculates whether or not there is a position where the own vehicle 100can park, from the analyzed environment information and the coordinateposition of the own vehicle 100 inputted from the own vehicle positionestimation unit 302. The parkable position may not be found, or multipleparkable positions may be found. Therefore, as an example of analysiscontents, when there is a parking space having a width, a length, and aheight equal to or more than those of the own vehicle 100 around the ownvehicle 100, the space is set as the parking candidate position, ananalysis result of the coordinate position (parkable space information)of the parking candidate and the parking candidate surroundingenvironment (environment information of the parkable space) istransmitted to the parking environment evaluation unit 303 and theonboard display device 15.

The present embodiment exemplifies the environment information aroundthe own vehicle 100 captured by the onboard cameras (each camera of thefront camera 2, the right camera 3, the rear camera 4, and the leftcamera 5) as an example of input, but the environment information may beobtained by analyzing based on information of sensors using sound waveor light. Further, when there is a parking space having a width, alength, and a height equal to or more than those of the own vehicle 100,that space is set as the parking candidate, but the parking candidatemay be detected by a parking frame, a parking lot information sign, orthe like.

The own vehicle position estimation unit 302 and a part of the parkableposition calculation unit 301 form a parkable space informationacquisition unit configured to acquire parkable space information(parking candidate frames 901, 1001, and 1003) where the own vehicle 100can park, from the surrounding environment information acquired by thefront camera 2, the right camera 3, the rear camera 4, and the leftcamera 5, while a part of the parkable position calculation unit 301forms a parking environment detection unit configured to detect thesurrounding environment information 902 and 1002 (see FIGS. 9 and 10) ofthe parkable space from the external surrounding environment informationand the parkable space information.

The parking environment evaluation unit 303 evaluates a parkingcandidate (the parking space, the target parking frame 1101 (see FIG.11)) based on each piece of information of the coordinate position ofthe parking candidate calculated by the parkable position calculationunit 301 and surrounding environment information of the parkingcandidate, the coordinate position of the own vehicle 100 calculated bythe own vehicle position estimation unit 302, the preference information15 a 1 stored in the preference information storage unit 15 a of theonboard display device 15, and information on presence or absence of apassenger of the own vehicle 100 detected by the human sensor 16. As anexample of the evaluation method, there is a method of representingevaluation of each item of the preference information 15 a 1, which iscomposed of a plurality of evaluation items, by a score, and increasingthe evaluation score of a candidate as the parking candidate conforms tothe preference information 15 a 1 of the passenger for a parking place.Further, the parking environment evaluation unit 303 is adapted tochange the score of the evaluation based on whether the passenger is onor off the own vehicle 100 specified by the human sensor 16. The abovecalculated evaluation result is transmitted to the target parkingposition calculation unit 304.

Based on the evaluation result of each parking candidate evaluated bythe parking environment evaluation unit 303, the target parking positioncalculation unit 304 sets, among the parking candidates, a parkingcandidate having a highest evaluation as a target parking position,which is a parking place to be targeted, and transmits to the onboarddisplay device 15 and the vehicle control ECU 17. If the evaluations areequal, it is possible to select the target parking position inconsideration of conditions, such as the one closer to the own vehicle100 and the one that is easy to park from the current travelingdirection.

The parking environment evaluation unit 303 and the target parkingposition calculation unit 304 form a parking space determination unitconfigured to determine a parking space to be parked with the ownvehicle 100 based on the coordinate position of the parking candidate,the parking candidate surrounding environment, and the preferenceinformation 15 a 1.

The onboard display device 15 visually notifies the driver of a locationand surrounding environment information of the parking candidate, and atarget parking position by superimposing the coordinate position of theparking candidate calculated by the parkable position calculation unit301 with the surrounding environment information of the parkingcandidate, and the target parking position calculated by the targetparking position calculation unit 304, on an image of surroundings ofthe own vehicle 100, and displaying on the screen 15 b of the onboarddisplay device 15.

As described above, the vehicle control ECU 17 allows the driver toreceive appropriate parking assistance during the operation for parkingat the above target parking position, by outputting a control signalnecessary for supporting a movement of the own vehicle 100 toward thetarget parking position to the electric power steering device 6, thedriving force control ECU, and the braking force control ECU of the ownvehicle 100 in order to assist a parking operation during parking at thetarget parking position.

Next, a specific example of the preference information 15 a 1 to be usedin the parking environment evaluation unit 303 will be described withreference to FIGS. 4 and 4A. FIG. 4 is an example of an outline of thepreference information 15 a 1 of a passenger for a parking environment,stored in the preference information storage unit 15 a of the onboarddisplay device 15. FIG. 4A is a view showing a state of setting thepreference information 15 a 1 of the passenger for a parking position.

First, the preference information 15 a 1 is information related toconvenience when a passenger who rides on the own vehicle 100 gets onand off, in other words, it is information on matters and tendenciesthat the passenger gives priority when selecting a parking section, andit is information on passenger's specific and dependent conditions thatare required when getting on and off. In addition, it is information ona request and wish when the passenger gets on and off the own vehicle100, and information on matters and conditions to be avoided.

For example, in item No. 1 shown in FIG. 4, a preference detail for“illuminance (brightness) of the parking environment” when the passengergets on and off is set. In a case where the passenger prefers a brightenvironment when getting on or off the vehicle, increasing weighting ofitem No. 1 causes evaluation of a parking candidate that is in a brightenvironment to become high when the parking environment evaluation unit303 evaluates the parking candidate, and there is a high possibilitythat parking assistance to a bright place will be performed.

Further, regarding “road surface (puddle)” of item No. 3, in a casewhere the passenger dislikes that there is a puddle in the parkingenvironment, setting a negative value as the weighting causes theevaluation to be lowered when the parking environment evaluation unit303 evaluates the parking candidate, and the possibility of parkingassistance to near a puddle is lowered.

As described above, the passenger weights for the preference of theparking environment, so that the preference of the passenger for theparking environment can be reflected more accurately on the targetparking position.

Further, such as item No. 15, a parking candidate for which a targetuser is limited such as a parking space for disabled people and the likecan be unselectable as the target parking position by setting theparking candidate to be out of the parking target.

Furthermore, the preference of the passenger for the parking environmentmay change depending on the weather. Therefore, as an example, when theweather is rainy, weighting of each item as shown in FIG. 4 is to bechanged.

For example, there is a problem that a parking lot having a road surfacemade of wood is slippery. Therefore, in a case where the passengerdislikes it, the weighting of item No. 11 of “road surface (wood)” inrainy weather is set to −5. This lowers evaluation of a parkingcandidate having a road surface made of wood in the parking environmentevaluation unit 303, and reduces the possibility for the parkingcandidate to be determined as the target parking position in rainyweather.

Meanwhile, regarding the preference information 15 a 1 when thepassenger gets on and off, items are exemplified such as, as shown inFIG. 4, illuminance, a size of the parking space, a road surfacecondition of the parking space (puddle, lawn, asphalt, gravel, mud,snow, fallen leaves, metal plate, and wood), presence or absence of aroof above the parking space, a traffic volume around the parking space,a number of parked vehicles around the parking space, and whether theparking space is an exclusive parking space for disabled people and thelike, but the above are not all, and the preference information 15 a 1can be set as appropriate.

Further, as a parking assist function by the parking assist apparatus,there is known an automatic parking function in which all the passengersincluding the driver get off when the vehicle has arrived at the parkinglot, the own vehicle 100 is automatically driven in a state where thepassenger is absent, a parkable position is searched for, a targetparking position is determined, and parking is performed.

During such automatic parking, necessity for taking into considerationof the preference detail when the passenger gets on and off is small.For this reason, it is possible to detect the presence or absence of thepassenger by the human sensor 16, and to change the weighting for eachitem number depending on the presence or absence of the passenger asshown in FIG. 4. This change can be made by the passenger using theonboard display device 15, or the change can be automatically made.

As an example, regarding to item No. 1 “illuminance (brightness) of theparking environment” shown in FIG. 4 described above, possibility ofconcerning the “brightness of the parking environment at getting on andoff” is low with the above-described automatic parking function as thepassenger is absent. Therefore, the weighting when the passenger isabsent is set to 0. This makes it possible not to affect determinationof the target parking position. Further, in order to prevent the ownvehicle 100 from becoming dirty due to a change in the weather, settingthe weighting of the presence or absence of a roof at item No. 12 whenthe passenger is absent to 5 raises evaluation of a parking candidatehaving a roof in the parking environment evaluation unit 303, andincreases possibility that the parking candidate is determined as thetarget parking position.

In such preference information 15 a 1, as shown in FIG. 4A, thepassenger can input and appropriately change the weighting for thepredetermined preference detail with use of an input column 15 b 1 byselecting an evaluation item to be changed on the pressure sensitive orthe electrostatic screen 15 b of the onboard display device 15 tohighlight the item to be changed. The method for inputting and changingthe weighting is not limited to this, as long as the evaluation item canbe selected and the weighting can be changed.

Next, a procedure from a start of parking assistance by the parkingassist apparatus to a completion of parking will be described withreference to FIG. 5. FIG. 5 is a flowchart describing a parking assistprocessing procedure by the parking assist apparatus shown in FIG. 1.

First, in step S501, the parking assist apparatus determines whether ornot the passenger of the own vehicle 100 has requested a start ofparking assistance. For example, in entering a parking lot to park theown vehicle 100, it is determined whether or not the passenger hasperformed a process of starting the parking assistance by using thetouch panel mounted on the onboard display device 15. When it isdetermined that the request has been made, the process proceeds to stepS502. On the other hand, when it is determined that the request has notbeen made, that is, when the passenger does not perform the process ofstarting parking assistance, the process is returned to before stepS501, and the process of step S501 is performed again. In other words,the parking assist apparatus waits until the passenger starts parkingassistance.

Although the determination to start the parking assistance in step S501is made through an operation of the touch panel mounted on the onboarddisplay device 15, the parking assistance may be automatically startedby detecting that the own vehicle 100 has entered a parking lot by usinga global positioning system (GPS) mounted on the own vehicle 100.

Next, in step S502, a sentence to prompt search of a parkable positionis displayed on the screen 15 b of the onboard display device 15. Thedriver confirming the above display manually drives the own vehicle 100.During the driving, the front camera 2, the right camera 3, the rearcamera 4, and the left camera 5 of the own vehicle 100 captureenvironment information around the own vehicle 100. Further, theparkable position calculation unit 301 analyzes the captured environmentinformation around the own vehicle 100, calculates the parkable positionof the own vehicle 100, when a parkable position is found, sets theparkable position as a parking candidate, and stores the parkingcandidate and the surrounding environment information. After searchingfor a parking candidate for a certain time, the process proceeds to stepS503.

In step S503, it is determined whether or not a parking candidate hasbeen found in step S502. When it is determined that a parking candidatehas been found, the parking candidate and the surrounding environmentinformation are superimposed on an image of surroundings of the ownvehicle 100 and displayed on the screen 15 b of the onboard displaydevice 15, and the process proceeds to step S504. By displaying on thescreen 15 b, it is possible to visually notify the driver of a locationof the parking candidate and surrounding environment informationthereof. As an example of the environment information, by displaying thepresence or absence of a puddle, the driver can save effort for checkingthe condition of the parking candidate with his/her own eyes, andconfirming the presence or absence of a puddle. On the other hand, ifthe parking candidate cannot be found, the process returns to step S502and the search for the parking candidate is continued.

In step S504, one or more found parking candidates are evaluated. As anexample of the evaluation method, as described in FIG. 4, based on thepreference information 15 a 1 of the passenger for parking environmentinputted by the passenger in advance, evaluation is performed as towhether or not the surrounding environment of the parking candidate issuitable for the preference information. At this time, as describedabove, the evaluation is performed in consideration of the weather andthe presence or absence of the passenger of the own vehicle 100 by thehuman sensor 16. Thereafter, the process proceeds to step S505.

In step S505, it is determined whether or not an evaluation score of oneor more parking candidates is equal to or higher than a threshold value.When it is determined that there is a parking candidate having a scoreequal to or higher than threshold value, in other words, when one ormore parking candidates that are considered to sufficiently satisfy thepassenger's preference are found, the parking candidate having a highestevaluation score is stored, and the process proceeds to step S507. Whenthe evaluation values are equal, the candidate of the one that is easyto park is selected according to a state of the own vehicle 100. On theother hand, when it is determined that the evaluation score of theparking candidate is less than the threshold value, that is, if noparking candidate that is considered to sufficiently satisfy thepassenger's preference is found, the parking candidate having a highestevaluation score is stored, and the process proceeds to step S506.

Next, step 506 will be described. In step S506, it is determined whetheror not a predetermined time has passed since “a parking candidate havinga highest evaluation score although it is not equal to or higher thanthe threshold value” stored in step S505 has been found and stored. Whenit is determined that the predetermined time has passed, the processproceeds to step S507. That is, if a parking candidate having anevaluation score equal to or higher than the threshold value cannot befound even when the parking assistance starts and a time for searching aparking candidate has passed for a predetermined time, it is avoided tokeep driving the own vehicle 100 in the parking lot for searching forthe parking candidate by proceeding to step 507. On the other hand, whenit is determined that the predetermined time has not passed, the processreturns to step S502 to continue searching for a parking candidatehaving an evaluation score equal to or higher than the threshold value.

In step S507, the parking candidate stored in step S505 is determined asthe target parking position, and the process proceeds to step S508.

In step S508, on the screen 15 b of the onboard display device 15, asentence for notifying the end of the search for the parking candidateis displayed, and a sentence to prompt to stop the own vehicle 100 isdisplayed. Further, by superimposing the determined target parkingposition on an image of surroundings of the own vehicle 100 anddisplaying on the screen 15 b of the onboard display device 15, thedriver is clearly notified where to park visually.

In step S509, parking assistance toward the target parking position isstarted, and the vehicle control ECU 17 appropriately controls the ownvehicle 100 in order to support a parking operation.

In step S510, when the own vehicle 100 completes the parking at thetarget parking position, the driving support is terminated, and asentence notifying that the parking has been completed is displayed onthe screen of the onboard display device 15.

By taking a procedure of the steps from step S501 to step S510, thetarget parking position can be automatically determined in considerationof the passenger's preference at getting on and off in the parkingassistance of the own vehicle 100.

Next, a state from the start of parking assistance by the parking assistapparatus of the present embodiment to the completion of parking will bedescribed below with reference to FIGS. 6 to 13. FIGS. 6 to 13 are viewsfor explaining a state of parking assistance by the parking assistapparatus shown in FIG. 1.

FIGS. 6 to 13 show a state of a parking lot viewed from the above andcontents displayed on the screen 15 b of the onboard display device 15,and are arranged in a chronological order of FIG. 6 to FIG. 13. Further,a parking assist function is used in order to park the own vehicle 100in an available parking space in the parking lot, and symbols P1 to P8denoted by reference numerals 601 to 608 are symbols uniquely indicatingrespective parking spaces in consideration of the convenience ofexplanation. Other vehicles are parked in parking spaces P1, P2, P3, P5,and P6, there is a puddle 609 in P4, and P7 is an exclusive parkingspace for disabled people and the like. The screen 15 b of the onboarddisplay device 15 displays a surrounding image of the own vehicle 100 asif viewing the own vehicle 100 from directly above, which is created bycombining images captured by the front camera 2, the right camera 3, therear camera 4, and the left camera 5. Regarding the preference detailwhen the passenger gets on and off, the one shown in FIG. 4 is referredto as an example.

First, as shown in FIG. 6, when entering a parking lot to park the ownvehicle 100, the passenger such as a driver presses a parking assistancestart button 611 displayed on the screen of the onboard display device15. This causes parking assistance to be started. This FIG. 6 is aprocess corresponding to step S501 of the flowchart of FIG. 5.

Next, as the passenger instructs a start of the parking assistance, asentence prompting the passenger to search for a parking candidate bydriving inside the parking lot, such as a sentence 701, is displayed onthe screen of the onboard display device 15 as shown in FIG. 7.

In a state where the parking candidate is not found, a sentenceprompting the passenger to search for a parking candidate by drivinginside the parking lot, such as the sentence 701, is continuouslydisplayed on the screen of the onboard display device 15 as shown inFIG. 8.

When the parking space P4 is found as a parking candidate, on the screenof the onboard display device 15 as shown in FIG. 9, the parkingcandidate frame 901 indicating that the parking space P4 has become aparking candidate and surrounding environment information 902 thereofare displayed. However, since an evaluation score of the parkingcandidate is less than the threshold value due to presence of a puddlein the parking space P4, and the parking candidate has not become thetarget parking position, the surrounding environment information 902indicating “there is a puddle” is displayed. By displaying thissurrounding environment information 902, the passenger can confirm thatthe parking candidate does not match the own preference without checkingby himself/herself. In FIG. 9, since the target parking position has notyet been determined, the sentence 701 prompting the passenger to searchfor a parking candidate by driving inside the parking lot is continued,and the driver continues driving of the own vehicle 100. The detaildescribed with reference to FIGS. 7, 8, and 9 is a process correspondingto steps S502 to S506 of the flowchart of FIG. 5.

Further, when the parking spaces P7 and P8 are found by continuingsearching for a parking candidate by driving inside the parking lot, onthe screen of the onboard display device 15 as shown in FIG. 10, theparking candidate frame 1001 is superimposed and displayed on theparking space P7, and the parking candidate frame 1003 is superimposedand displayed in the parking space P8, where the parking candidateframes 1001 and 1003 indicate that the parking spaces P7 and P8 arefound as parking candidates.

Among the found parking spaces, since the parking space P7 is anexclusive parking space for disabled people and the like, surroundingenvironment information 1002 of “out of target” indicating that theparking space P7 is not to be selected as the target parking position isdisplayed together with the parking candidate frame 1001 as shown inFIG. 10. Displaying such surrounding environment information 1002 allowsthe passenger to confirm that the parking space P7 is not to be selectedas the target parking position.

On the other hand, regarding the parking space P8, since the evaluationresult of the surrounding environment of the parking candidate P8 hasshown that the evaluation score is equal to or higher than the thresholdvalue, the target parking frame 1101 is displayed on the screen 15 b ofthe onboard display device 15 as shown in FIG. 11, instead of theparking candidate frame 1003, in order to indicate the parking candidateP8 as the target parking position to the passenger. Further, because thetarget parking frame has been determined, a sentence 1102 prompting thedriver to stop the own vehicle 100 is displayed. The detail describedwith reference to FIGS. 10 and 11 is a process corresponding to steps507 to S508 of the flowchart of FIG. 5.

Thereafter, as shown in FIG. 12, the driver stops the own vehicle 100and starts a parking operation. In order to park in the target parkingframe 1101, the parking assist apparatus displays a sentence 1201prompting the driver to perform a predetermined parking operation, andassists the parking operation with the vehicle control ECU 17 when thedriver starts the parking operation. FIG. 12 is a process correspondingto step 509 of the flowchart of FIG. 5.

Thereafter, as shown in FIG. 13, parking of the own vehicle 100 in thetarget parking frame 1101 is completed by the parking assistance. Uponcompletion, the parking assist apparatus displays, on the screen of theonboard display device 15, a sentence 1301 notifying the passenger thatthe parking has been completed, and the parking assistance function isterminated. FIG. 13 is a process corresponding to step 510 of theflowchart of FIG. 5.

Next, effects of the present embodiment will be described.

The parking assistance apparatus of the present embodiment describedabove acquires information on the parking candidate frames 901, 1001,and 1003 where the own vehicle 100 can park, from the front camera 2,the right camera 3, the rear camera 4, and the left camera 5 configuredto acquire information on the surrounding environment of the own vehicle100, and from the surrounding environment information acquired by thesecameras. Further, the parking assistance apparatus detects thesurrounding environment information 902 and 1002 of the parkingcandidate frames 901, 1001, and 1003 from the surrounding environmentinformation and information on the parking candidate frames 901, 1001,and 1003, and determines the target parking position where the ownvehicle 100 parks based on the information on the parking candidateframes 901, 1001, and 1003, the surrounding environment information 902and 1002, and the preference information 15 a 1 related to getting onand off of the passenger who rides on the own vehicle 100.

By determining the target parking position with use of the preferenceinformation 15 a 1 related to getting on and off of the passenger whorides on the own vehicle 100 in this way, the preference of thepassenger at getting on and off is more accurately reflected in thesearch of the target parking position, enabling improvement ofconvenience at getting on and off of the own vehicle 100. Further, byacquiring and analyzing the surrounding environment information of theown vehicle 100 with each sensor mounted on the own vehicle 100, it ispossible to acquire more detailed and real-time information than theinformation analyzed by a facility in the parking lot, enabling accuratesearch of the target parking position that is more suited to thepreference detail of the passenger at getting on and off.

Further, since the preference information 15 a 1 is composed of aplurality of evaluation items, it is possible to search for the targetparking position reflecting the preference of the passenger at gettingon and off more finely, enabling further improvement of the convenienceat a time of getting on and off.

Furthermore, since there is further provided the onboard display device15 for the passenger of the own vehicle 100 to input the preferenceinformation 15 a 1, it is possible to easily set and change thepreference information 15 a 1, enabling more accurate reflection of thepreference at a time of getting on and off.

Further, since weighting of the evaluation items can be changed throughthe onboard display device 15, it is possible to suitably change thepreference of the passenger at getting on and off, enabling parkingassistance with improved convenience.

Furthermore, it is not always necessary to reflect the preferenceinformation 15 a 1 when the passenger is absent, and it is conceivablethat the choice of the target parking position is to be expanded.Therefore, there is further provided the human sensor 16 configured tospecify the presence or absence of the passenger of the own vehicle 100,and the parking environment evaluation unit 303 and the target parkingposition calculation unit 304 change the weighting of the plurality ofevaluation items based on the presence or absence of the passengerspecified by the human sensor 16, enabling a more flexible search of thetarget parking position to be performed.

Further, by further providing the screen 15 b to display the parkingcandidate frames 901, 1001, and 1003 and the surrounding environmentinformation 902 and 1002, the passenger of the own vehicle 100 caneasily grasp the target parking position or a reason for beinginappropriate as the target parking position during parking, enablingimprovement the convenience at a time of parking as well.

Furthermore, regarding the convenience at a time of getting on and offin parking, there are a large number of items that are largelyinfluenced by the weather. In this regard, by enabling the parkingenvironment evaluation unit 303 and the target parking positioncalculation unit 304 to change the weighting of the plurality ofevaluation items based on the weather, the parking assistance accordingto a state of the surroundings of the own vehicle 100 becomes possibleand the convenience at a time of getting on and off can be furtherimproved.

Further, by setting the evaluation item of the preference information 15a 1 to be at least one or more of a illuminance, a size, a road surfacecondition, presence or absence of a roof above, a traffic volume in thesurroundings, or a number of parked vehicles in the surroundings of theparking candidate frames 901, 1001, and 1003, it is possible to performparking assistance in consideration of the surrounding environment at atime of getting on and off, enabling further improvement of theconvenience.

Further, by setting the road surface conditions of the parking candidateframes 901, 1001, and 1003 such that the road surface is at least one ormore of a puddle, a lawn, an asphalt, a gravel, a mud, a snow, a fallenleaf, a metal plate, or wood, it is possible to perform parkingassistance reflecting the item related to the convenience of underfootof the passenger at getting on and off, enabling further improvement ofthe convenience.

<Others>

Note that the present invention is not limited to the above embodiment,and various modifications may be included. For example, the embodimentdescribed above has been illustrated in detail to facilitate descriptionfor easy understanding of the present invention, and is not necessarilylimited to the embodiment that includes all the configurations.

For example, control lines and information lines indicate what isconsidered to be necessary for the description, and do not necessarilyindicate all the control lines and the information lines on the product.In practice, it can be considered that almost all the structures aremutually connected.

REFERENCE SIGNS LIST

-   1 parking-assist ECU-   2 front camera-   3 right camera-   4 rear camera-   5 left Camera-   6 electric power steering device-   6 a steering angle sensor-   7 right front wheel-   8 right rear wheel-   9 left rear wheel-   10 left front wheel-   11 right front wheel speed sensor-   12 right rear wheel speed sensor-   13 left rear wheel speed sensor-   14 left front wheel speed sensor-   15 onboard display device-   16 human sensor-   15 a preference information storage unit-   15 a 1 preference information-   15 b screen-   15 b 1 input column-   17 vehicle control ECU-   18 steering wheel-   100 own vehicle-   301 parkable position calculation unit-   302 own vehicle position estimation unit-   303 parking environment evaluation unit-   304 target parking position calculation unit-   601, 602, 603, 604, 605, 606, 607, 608 parking space-   611 parking assistance start button-   701, 1102, 1201, 1301 sentence-   901, 1001, 1003 parking candidate frame-   902, 1002 surrounding environment information-   1101 target parking frame

The invention claimed is:
 1. A parking assist apparatus comprising: anexternal information acquisition unit configured to acquire externalinformation of an own vehicle; a parkable space information acquisitionunit configured to acquire information on a parkable space where the ownvehicle can park, from the external information acquired by the externalinformation acquisition unit; a parking environment detection unitconfigured to detect environment information of a parkable space fromthe external information and the parkable space information; apreference information storage unit configured to store preferenceinformation related to getting on and off of a passenger who rides onthe own vehicle; and a parking space determination unit configured todetermine a parking space where the own vehicle is to be parked based onthe parkable space information, the environment information, and thepreference information, wherein the preference information is composedof a plurality of evaluation items, and the parking space determinationunit changes weighting of the plurality of evaluation items based onweather.
 2. The parking assist apparatus according to claim 1, furthercomprising a preference information input unit for a passenger of theown vehicle to input the preference information.
 3. The parking assistapparatus according to claim 2, wherein weighting of the evaluationitems can be changed through the preference information input unit. 4.The parking assist apparatus according to claim 3, further comprising ahuman sensor configured to specify presence or absence of a passenger ofthe own vehicle, wherein the parking space determination unit changesweighting of the plurality of evaluation items based on presence orabsence of a passenger specified by the human sensor.
 5. The parkingassist apparatus according to claim 1, further comprising an environmentinformation display unit configured to display the parkable space andthe environment information.
 6. The parking assist apparatus accordingto claim 1, wherein an evaluation item of the preference information isat least one or more of an illuminance of a parkable space, a size of aparkable space, a road surface condition of a parkable space, presenceor absence of a roof above a parkable space, a traffic volume around aparkable space, or a number of parked vehicles around a parkable space.7. The parking assist apparatus according to claim 6, wherein a roadsurface condition of the parkable space is that a road surface is atleast one or more of a puddle, a lawn, an asphalt, a gravel, a mud, asnow, a fallen leaf, a metal plate, or wood.